Bag filling machines which are arranged vertically frequently receive a tubular plastic bag structure which is pinched off at the bottom portion to form a bottom closure for the bag, the top of the bag being secured around a filling tube which expands, upwardly, into a filling funnel, through which the products to be filled into the bag are introduced. After filling, the bag is permitted to drop down, and the top of the bag is pinched off with a dual pinch or weld seam, the lower portion of the pinch or weld seam forming the seal for the just filled bag and the upper portion the bottom for a next bag to be filled.
Light filling goods or products are difficult to fill that way, or require an excessively large bag, since the fill good, upon dropping down through the funnel, may not fall straight, and be subjected to floating due to air resistance and planing effects. Typical fill goods which are light and of large areas are, for example, potato chips, popcorn and the like. Such large-surface light products have the tendency to "dance" in uncontrollable manner within the filling tube or the filling funnel, and to drop only slowly. It is absolutely necessary that the fill good is entirely within the bag and clearly below the seam line to be produced in closing the bag. This is necessary for safety and hygenic reasons. Thus, no portion of the product may fall within pinching jaws which seal off the top of the tube. The slowness of filling reduces the rate of machine output and the excess space in the fill bag requires additional material.